1. Field of the Invention
The present invention relates to an integrated process for the production of isoolefin by the dehydration of isoalcohol and the synthesis of a corresponding ether. More particularly the invention relates to the first stage concurrent dehydration of tertiary butyl alcohol, recovery of isobutene and the second stage concurrent etherification of the recovered isobutene with an alcohol and recovery of ether.
2. Related Art
Methyl tertiary butyl ether (MTBE) is a useful component for improving the octane of gasolines and has commonly been prepared by the acid catalyzed reaction of methanol with isobutene. Examples of such a process are disclosed in U.S. Pat. Nos. 4,039,590 and 4,198,530.
Recently a new method of carrying out catalytic reactions has been developed, wherein the components of the reaction system are concurrently separable by distillation, using the catalyst structures as the distillation structures. This method is now generally known as catalytic distillation and any reference to catalytic distillation herein will be taken to mean this method or process. Such systems are described variously in U.S. Pat. Nos. 4,215,011; 4,232,177; 4,242,530; 4,302,356; 4,307,254; 4,336,407; 4,439,350; 4,443,559; and 4,482,775. U.S. Pat. No. 4,447,668 discloses the dissociation of ethers in a catalytic distillation column.
U.S. Pat. No. 3,267,156 discloses the preparation of dialkyl ethers by dehydration over acid resin catalyst at 250 to 400.degree. F.
U.S. Pat. No. 4,827,048 discloses the production of MTBE using heteropoly acid catalyst on an inert support to dehydrate methanol and tertiary butyl alcohol in a straight pass reaction at 120.degree. F.+.
U.S. Pat. No. 4,918,244 disclosed MTBE production by reacting methanol and tertiary butyl alcohol in a rectification tower in a packed bed.